Te
Pou
Oranga Kai
O Aotearoa
Operational Guideline:
Design and Construction of Dairy Premises
and Equipment
13 April 2006
New Zealand Food Safety Authority
PO Box 2835, Wellington, New Zealand
13 September 2005
Acknowledgments
NZFSA wishes to acknowledge the contribution from the dairy industry in the review/development
of this code into guideline format.
2
Table of Contents
1.0
Introduction ..................................................................................... 4
2.0
New or Significantly Altered Dairy Premises and/or Plant ...... 10
3.0
Layout of the Site.......................................................................... 16
4.0
Layout for Buildings .................................................................... 17
5.0
Design and Construction of Buildings...................................... 23
6.0
Building Services......................................................................... 31
7.0
General Requirements for Manufacturing Equipment ............. 41
8.0
Layout of Manufacturing Equipment.......................................... 45
9.0
Process engineering .................................................................... 47
10.0
Requirements for Specific Types of Equipment ...................... 53
3
1.0 Introduction
1.1
Background to the Development of this Guideline
Criteria relating to the design and construction of Dairy Premises and plant were originally
published by MAF within the documents DDM1A, DDM1B, DDM1C. The ownership of these
documents was then transferred to MQM and the documents were renamed as MQD1A, MQD1B,
MQD1C.
These precursor documents were then reviewed by an industry working group and published by
the New Zealand Dairy Board (NZDB) as NZCP6 (Design and Layout of Manufacturing Premises)
This review was funded by the NZDB, and copyright was vested with the NZDB.
NZCP6 was approved by MAF as a Code of Practice for the NZ Dairy Industry. It was, and is,
widely regarded within the NZ industry as a benchmark for the design and construction of Dairy
Plants and Premises.
In 2005, Fonterra transferred copyright of NZCP6 to NZFSA. This transfer has enabled NZFSA to
review the document and to develop the NZFSA Guideline for the Design and Construction of
Dairy Premises and Equipment.
1.2
What is the purpose of this guideline?
All operations involving dairy material processing intended for export must be conducted in
accordance with the requirements of an approved Risk Management Programme. The approval
of the RMP will include consideration of the issues covered in this Guideline (e.g. buildings,
equipment, building services and amenities).
This guideline does not cover laboratories, farm dairies or stores. [Location will be advised as
become available].
This purpose of this guideline is to provide information to dairy stakeholders concerning the
production of safe product with regard to the following areas:
• Technical guidance material, regarding the design, construction and approval of dairy
premises, by which the RMP can be deemed to be compliant in the areas of premises
and equipment
• NZFSA prior evaluation process of sections of the RMP relating to premises and plant
design and construction. Note that this prior approval process is a non mandatory process
developed to assist the dairy industry. It is recommended that the prior evaluation process
is followed in order to minimise the risk of potentially costly conditions being imposed at
time of RMP assessment.
This guideline should be read in conjunction with relevant market requirements e.g.
ICR’s/OMARS.
It is intended that this guideline be applied to new or significantly altered premises or plants.
4
1.3
What is included in this guideline?
This guideline sets out standards and guidelines for the design and construction of premises and
equipment used for the manufacture and processing of dairy products and transport of bulk milk
and liquid milk products.
This guideline is relevant to the requirements of the Animal Products Act 1999. Whilst this
document is prepared for the dairy industry, it may provide assistance to other food
manufacturers.
Food premises will also need to comply with other regulatory requirements (e.g. OSH) and
specific processing requirements and the requirements of local authorities, especially the
Resource Management Act 1991 and the Building Act 1992.
This guideline provides technical information for the hygienic design and construction of dairy
manufacturing premises and equipment. It also satisfies NZFSA requirements for RMP approval.
1.4
What are the desired outcomes?
It is expected that after reading this guideline dairy processors will have gained technical
information regarding the requirements for hygienic design and construction of premises and
equipment. Conformance with the technical material in this guideline will facilitate RMP approval
in the areas of premises and plant design and construction.
1.5 Glossary of terms
These definitions must be read in conjunction with the interpretations in the Animal Products Act
1999 and the Animal Products (Dairy) Regulations 2005.
NZFSA definitions of terms can be found in the “Glossary of Terms,” available on the Dairy &
Plants website (www.nzfsa.govt.nz/Dairy/).
Dairy Material means animal material that is - milk extracted from a milking animal
- any material derived or processed from milk extracted from a milking animal, up until delivery of
the material at the place of sale for consumption or for end use for purposes other than
consumption, or its export; and
- includes dairy product that, having been purchased or imported, is further processed.
Equipment means all apparatus, containers, conveyances, machinery, piping, pumps, utensils,
vehicles, and other things used in the transport, reception, testing, grading, manufacture, or
storage of milk.
5
“Fit for intended purpose” – The phrase “fit for intended purpose”, used in relation to animal
product that has been processed in accordance with Parts 2 to 4, means that, by reason of animal
material or product having had the relevant risk factors managed in accordance with Parts 2 and
3, and meeting any relevant animal product standards and associated specifications set under
Part 4, the product is suitable for the purpose for which the product is specifically stated or could
reasonably be presumed to be intended having regard to its nature, packaging and identification.
Manufacture (Dairy Processing) All processing activities in relation to dairy material, including
milking, transport, processing, addition of other material, manufacture, packaging, and storage.
Must expresses a requirement of the Animal Products Act 1999.
Recognised agency In relation to any function or activity, means a person or body recognised
under section 103 for the purpose of performing that function or activity
Shall expresses a mandatory requirement, sourced from NZFSA requirements and which is
reiterated in this guideline.
Should expresses a recommended provision which when followed may improve the design.
Significant amendments to risk management programme –
(1) The operator of a registered risk management programme must amend that programme, and
apply for registration of the amendment, where any change, event, or other matter means that the
programme (a) is no longer appropriate, or will no longer be appropriate, to the animal material or product,
processes, or premises or place covered by the programme; or
(b) otherwise impacts, or will impact, on the fitness for intended purpose of the animal product
concerned or the content of the risk management programme as required under section 17 (1).
For more information
Contact:
Dianne Schumacher
Senior Programme Manager (Technical Standards – Dairy)
Phone: 04 463 2500 or 06 762 8701
Mobile:021 724 862
Email: dianne.schumacher@nzfsa.govt.nz
Or
Imogen Claridge
Advisor (Technical Standards and Systems)
Phone: 04 463 2500
Email: imogen.claridge@nzfsa.govt.nz
6
1.6 References
3A Sanitary Standards Inc. Relevant documents from 3A Sanitary Standards and Accepted
Practices series http://www.techstreet.com/3Agate.html in particular the following may be useful:
3A Sanitary Standards Inc. 3A Sanitary Standards for Silo-Type Storage Tanks for Milk and Milk
Products. Doc.No. 22-08 : 2004
3A Sanitary Standards Inc. 3A Sanitary Standards for Centrifugal and Positive Rotary Pumps for
Milk and Milk Products. Doc.No. 02-09 : 1996
3A Sanitary Standards Inc. 3A Sanitary Standards for Homogenisers and Reciprocating Pumps.
Doc.No. 04-04 : 1996
3A Sanitary Standards Inc. 3A Sanitary Standards for Filters Using Single Service Filter Media.
Doc.No. 10-04 : 2000
3A Sanitary Standards Inc. 3A Sanitary Standards for Plate Type Heat Exchangers. Doc.No. 1106 : 2001
3A Sanitary Standards Inc. 3A Sanitary Standards for Tubular Heat Exchangers. Doc.No. 12-07 :
2003
3A Sanitary Standards Inc. Batch and Continuous Freezers for Ice Cream, Ices, and Similarly
Frozen Dairy Foods . Doc.No. 19-05: 1999
3A Sanitary Standards Inc. 3A Sanitary Standards for Centrifugal Separators adn Clarifiers.
Doc.No. 21-00: 2002
3A Sanitary Standards Inc. 3A Sanitary Standards for Sifters for Dry Products. Doc.No. 26-04:
2001
3A Sanitary Standards Inc. Equipment for Packaging Dry Milk and Dry Milk Products. Doc.No.
27-05: 2002
3A Sanitary Standards Inc. Multiple-Use Rubber and Rubber-Like Materials Used as Product
Contact Surfaces. Doc.No. 18-03 : 1999
3A Sanitary Standards Inc. 3A Sanitary Standards for Multiple-Use Plastic Materials. Doc.No.
20-23 : 2004
3A Sanitary Standards Inc. 3A Accepted Practices for Permanently Installed Product and
Solution Pipelines and Cleaning Systems, Doc.No. 605-04 : 1994.
3A Sanitary Standards Inc. 3A Accepted Practices for Supplying Air under Pressure for Contact
with Product and Product Contact Surfaces. Doc.No. 604-04 :2004.
3A Sanitary Standards Inc. 3A Accepted Practices for a Method of Producing Culinary Steam.
Doc.No. 609-03 : 2004.
American Society of Heating, Refrigerating and Air Conditioning Engineers. ASHRAE Standard
52-76. Method of Testing Air Cleaning Devices used in General Ventilation for Removing
Venticulate Matter.
ASHRAE Handbook. 2003. HVAC Applications
AS 1668.2-2002 : The use of ventilation and air conditioning in buildings - Ventilation design for
indoor air contaminant control
AS 4254-2002: Ductwork for air-handling systems in buildings
British Standards Institute. BS 1134: 1988. Assessment of Surface Texture.
British Standards Institute. BS 1134-2: 1990. Assessment of Surface Texture Guidance and
General Information
7
Fonterra Co-operative Group Ltd. Fonterra Standard of Excellence 7, Pasteurisation Equipment
and Instrumentation. Fonterra Co-operative Group Ltd., Hamilton, 2005.
Fonterra Co-operative Group Ltd. NZTM 2: Microbiological Methods Manual.
operative Group Ltd., Hamilton, 2004.
Fonterra Co-
Fonterra Co-operative Group Ltd. NZTM 6: Sensory Methods Manual. Fonterra Co-operative
Group Ltd., Hamilton, 2004.
International Dairy Federation. IDF Bulletin 100/1977. Safety and Reliability of Automated Dairy
Plant.
International Dairy Federation. IDF Bulletin 117/1979. Design and Use of CIP Systems in the
Dairy Industry.
International Dairy Federation. IDF Bulletin 128/1980.
Construction of Milk Collection Tankers.
International Standards Organisation.
Requirements
Code of Practice for the Design and
ISO 9001: 2000 . Quality Management Systems -
International Standards Organisation. ISO 17020: 1998. General criteria for the operation of
various types of bodies performing inspection.
International Standards Organisation. ISO 14159: 2002.
requirements for the design of machinery.
Safety of Machinery – Hygiene
MAF Regulatory Authority (Dairy). Dairy Products Safe and True. Publishing Solutions Limited,
Wellington, 1998. www.nzfsa.govt.nz/dairy/publications/information-papers/dpst
NZ Dairy Board. NZCP 14: New Zealand Dairy Industry - Salmonella and Listeria Testing – Code
of Practice. Fonterra Co-operative Group Ltd., Hamilton, 1994.
NZ Ministry of Agriculture and Forestry. Specifications for Exotic Disease Control in the Dairy
Industry. MAF, Wellington, 2002.
NZ Ministry of Health. Drinking Water Standards for New Zealand 2000. NZ Ministry of Health,
Wellington, 2000.
NZ Ministry of Health. Drinking Water Standards for New Zealand 2005. NZ Ministry of Health,
Wellington, 2005
Occupational Safety and Health Service. Approved Code of Practice for the Prevention,
Detection and Control of Fire in NZMP Spray Drying Plant. Department of Labour, Wellington,
1993.
Sheet Metal and Air Conditioning Contractors' National Association (USA).
Construction (SMACNA)
HVAC Duct
Stainless Fabrication Group. Code of Practice for the Fabrication of Stainless Steel Plant &
Equipment. SFG, Hamilton, 1990.
Standards Association of New Zealand. NZS 4703: 1985. Welder Qualification Tests for Stainless
Steel Pipe for the Dairy Industry.
Standards Association of New Zealand. AS/NZS 1677: 1998. Refrigerating systems – Safety
requirements for fixed applications
8
Standards Association of New Zealand. NZS 5807: 1980. Industrial Identification by Colour,
Wording or Other Coding.
Standards Association of New Zealand. NZS 6703: 1984. Code of Practice for Interior Lighting
Design.
World Health Organisation. Guidelines for drinking-water quality, third edition. WHO, Geneva,
2004.
9
2.0 New or Significantly Altered Dairy Premises
and/or Plant
2.1
Introduction
The suitability of the premises and equipment shall be determined as part of the risk management
programme (RMP) assessment. However potential dairy processors may choose to apply for
prior assessment of the premises and equipment. The prior assessment process for new
premises or significant alterations is not mandatory but does provide the applicant with more
timely information regarding premises and equipment suitability.
2.2
Assessment of the Design and Construction of Dairy Premises
and Plant Components of an RMP
2.2.1 Registration Process for RMP including premises under an RMP
The process for prior assessment of new premises is outlined below:
1. RMP Operator develops the RMP or significant amendment to the RMP that covers the
premises concerned, and captures the premises specific requirements.
2. RMP Operator applies to NZFSA for unique location identifier, if new location.
3. NZFSA assign unique location identifier.
4. RMP Operator validates the RMP or RMP amendment.
5. RMP Operator submits the RMP or amendment to a dairy RMP evaluator recognised for
the appropriate product groups within the scope of the RMP.
6. Recognized dairy RMP evaluator–
a. ensures that a recognised premises evaluator assesses the design and
construction aspects.
b. ensures that a recognised heat treatment evaluator assesses dairy heat treatments
covered by the RMP or amendment.
c. provides an evaluation report and, if satisfactory, an endorsement to the RMP
Operator
7. RMP operator submits the evaluator endorsed RMP, the evaluator endorsed RMP outline,
or the evaluator endorsed RMP amendment to NZFSA for registration, along with the
appropriate application form, evaluation report and endorsement.
10
8. NZFSA registers the RMP with or without conditions (NZFSA to develop internal guidance
on which conditions are applied when).
9. NZFSA Approvals & Registrations Group notify CIG upon registration of the RMP or
amendment.
2.2.2 Information that may be required by the Recognised Agency (RA) from the RMP
Operator
The RA should be notified before construction work commences on new or significantly altered
premises which could impact on food safety. The notification should provide an overview of the
project . This initial notification should contain the following information where appropriate:
• the likely timetable for the work
• the proposed main contractor
• a summary of the proposed construction activities. As the project proceeds and further
information details becomes available, relevant details are provided to the RA. These
details may include:
General
•
•
•
•
•
•
the legal description of the site
description of where the site is located
the zoning of the premises and the surrounding properties
neighbouring industries with the potential to create food safety hazards
the intended methods of effluent disposal
the intended methods of waste air discharge.
Site location plan
The site location plan should show the proposed site in relation to the following:
•
•
•
•
•
boundaries
North
nearby roads
effluent disposal areas
dimensions or scale;
and where applicable:
•
•
•
nearby rivers, streams, swamps and other waterways
nearby railway lines
existing buildings on nearby sites and their use.
Site plan
The site plan should show the following to scale:
11
•
•
•
•
•
•
•
•
•
•
•
•
North
site boundaries
the location on the site of all existing and proposed buildings
service tunnels, where installed
clear labels showing the use planned for each part of the building
the location on the site of any special areas, other than existing and proposed
buildings, e.g. water treatment
all road and access ways, tanker washing areas and proposed tanker
movements on site
the location of any railway lines
the storm water collection system
the location of silos
on-site effluent drains and effluent treatment facilities
the prevailing wind direction.
Building layout plans
Building layout plans should show accurately the facilities as they will exist when the
premises is in operation. The items that should be shown where appropriate are:
•
•
•
•
•
•
•
•
the location of walls, columns, airlocks, stairs, windows, doorways and other
openings, such as ventilation inlets and outlets, conveyor openings, removable
panels, etc.
floor drainage, indicating the direction of fall and gradient, and the location of
drains and drain openings
if open channel drains are used, their fall, direction of flow and dimensions
details of drain inlets, traps and grills
the intended use of each area of the factory (e.g. hygiene zoning and wet and
dry zoning)
storage facilities for product and product ingredients
amenities, indicating lockers, toilet facilities, urinals, hand basins, showers, hand
washing and hand drying facilities
dimensions according to regulatory requirements and minimum standards.
Equipment layout plans
Equipment layout plans should show accurately:
•
•
the location and name of all but minor items of plant and equipment
all product lines, including conveying lines, roller conveyors, belt conveyors, etc.
CIP system drawings
A schematic drawing of the proposed cleaning-in-place (CIP) system should be
provided. It should show all items of plant intended to be cleaned-in-place, all
processing lines and all CIP lines. On this drawing, all major items of plant should be
named and the dimensions given.
A description of each cleaning circuit, including cleaning flow rates, and describing the
sequence of items in that circuit, should be included.
12
Cross-section drawings
Cross-section drawings should show the following details when they are not obvious
from other drawings:
•
•
•
•
•
•
•
the interior finish system for floors, walls and ceilings (or a finishes schedule)
covings
window ledges, trusses, platforms and supports where they occur within the
processing rooms
heights of ceilings
the position of principal items of plant, equipment and overhead gear
the construction materials, method of fixing and method of jointing of doors,
window frames, walls, ceilings and floors
dimensions.
Elevation drawings
Where appropriate, exterior elevations should be included to show clearly the location
and size of doors, windows and other openings, canopies, etc.
Drainage plan
The drainage plan should show clearly the effluent drainage system, the sanitary
sewerage system and the storm water system. The plan of the drainage system should
include all details within the site boundaries. The drainage plan should also show
rodding points. Where appropriate, site levels or contours should also be shown.
Proposed materials should be shown.
Ventilation plan
The ventilation plan should show the location of and access to inlets, filters, fans,
ducting, distribution points, exhausts and inspection points. If these details are clearly
shown on other plans, a separate ventilation system plan need not be supplied.
Lighting services plans
Unless the details are shown on other plans, a lighting services plan should be supplied.
The plan should show the location and type of lights to be installed (or a lighting
schedule).
General
Give:
•
•
•
•
•
•
the name of the company applying for approval
the date
the location of the proposed factory site
the products intended to be produced and the expected peak throughput or
capacity
a concise description of the proposed method of operation
the approximate increase in water demand, effluent load, ventilation load,
refrigeration load.
13
Materials schedule
This section may have been included in the specifications.
repeated.
If so, it need not be
Identify the construction materials and finish of the:
•
•
•
•
•
•
•
floors
inside walls
ceilings
jointings used on ceilings and inside walls
window frames
doors
drains inside processing areas and under processing floors.
Ventilation
Supply the type of air filter being used, or the appropriate specification.
For each processing room supply either:
•
evidence that ventilation meets the requirements of this code for minimum
overpressure and minimum airchanges, or
•
provide:
-
the air flow rate
an estimate of heat release, including steam and moisture
release, and
differential pressures
Equipment
Give:
•
•
•
•
a detailed written description of the equipment, outlining its intended end use
(including the products for which the equipment is designed)
details of the intended capacity of the equipment
full details of the composition of all product contact surfaces within the
equipment together with any relevant finish standards
a concise description of the proposed method of operation and cleaning.
Amenities
State whether the amenities comply with the relevant regulatory requirements.
2.2.3
Recognised agency (RA) undertakes assessment of proposal and construction
process. During the planning and Construction process, the RA will provide timely
written reports at intervals agreed with the Dairy Operator.
2.2.4 Where significant alterations are planned to an existing RMP, progress will be reported
14
by the RMP Operator as part of regular reporting to the RA.
2.2.5 At completion of the premises and /or plant construction the RA provides an evaluation
report.
2.2.6 The application for new or significantly altered RMP approval is submitted together with
the RA evaluation reports (which includes evaluation of premises and Plant design and
/ or construction).
15
3.0 Layout of the Site
3.1
Requirements for the Site
Product factories shall be located in areas free from objectionable odours, smoke, dust
and other contaminants which might be produced from neighbouring industries, or any
other hazards which could affect the safety of the dairy products.
It is advised that consideration should be given to such natural factors e.g. flooding and
the previous use of site e.g. soil pollutants.
3.2
Requirements for Site Layout
The layout of buildings and facilities on the site should minimize any hazard to product
safety.
Factors which should be taken into consideration when considering site layout include:
•
•
•
•
•
•
•
•
3.3
tanker access routes and wash areas
access routes for vehicles involved with waste removal
effluent storage, treatment and disposal areas
other vehicle access
fuel storage and handling facilities
ventilation and process air intakes and exhausts
staff access and amenities
prevailing winds.
Roads
Roads, traffic areas and access ways on the product factory site should be formed,
graded, sealed and sloped so that they drain surface water. They should be kerbed
where necessary to control traffic and drainage. Sufficient drainage should be provided
to convey water away from the premises and roadways. Section 4.9 contains additional
requirements for tanker unloading, loading and washing areas.
16
4.0
Layout for Buildings
4.1
General
The layout and construction of buildings must support good manufacturing practice. E.g. Areas in
which dairy produce is manufactured shall be designed:
a) to provide separation by partition, location or other effective means between operations
that may cause cross – contamination.
b) protect product from risk of contamination
c) and protect deterioration of product by exposure.
[NZFSA is shortly to publish a document “Pathogen Management Plan Guideline” which
will contain further information regarding Hygiene Zones.]
4.2
4.2.1
Hygiene Area Zoning
Critical Hygiene Areas are those areas in a product factory where environmental control
is necessary to prevent contamination of heat treated product after the heat treatment
step. There should be no raw milk in Critical Hygiene Areas. Processing equipment
should be placed in or open into a Critical Hygiene Area where any of the following are
routinely exposed to the environment:
•
pasteurised or heat treated milk and milk products which will not receive a
further pasteurising heat treatment,
•
product ingredients that are incorporated into the process stream after the
designated pasteurising heat treatment step,
•
product contact surfaces of packaging materials,
•
product contact surfaces in equipment that follow the pasteurising heat
treatment step in the process flow.
In some circumstances there may be justification for locating processes which are
inherently safe due to design and operating characteristics, in a Standard Hygiene Area
(e.g. UHT or similarly totally enclosed processing). However, this would be regarded as an
exception and would need to be discussed with the appropriate RA and NZFSA before
construction.
4.2.2
Standard Hygiene Areas are those areas in a product factory in which environmental
control is necessary to prevent contamination of milk and milk products prior to a
microbiocidal critical control point such as pasteurisation. Processing equipment should be
placed in a Standard Hygiene Area only where any of the following are routinely exposed
to the environment:
17
•
•
•
milk and milk products prior to a microbiocidal critical control point such as
pasteurisation,
product ingredients which are incorporated into the process stream before the
pasteurising heat treatment step,
product contact surfaces of equipment before the pasteurising heat treatment
step of the process.
Depending on individual circumstances and related food safety risks, the following
activities may need to be located in Standard Hygiene Areas:
•
•
•
4.3
Process equipment cleaning,
air filter washing, drying and sanitising
laundry of process hygiene overalls and other process protective clothing.
Isolation of Critical Hygiene Areas and Standard Hygiene Areas
It is recognised that some existing facilities may not be in full agreement with this guideline, in
such cases additional procedures to control food safety risks should be put in place, and will be
assessed on a case by case basis by the verifier. However it is recommended new/significantly
altered premises should adopt this guideline.
4.3.1
Critical Hygiene Areas should be isolated from all other parts of the factory including
Standard Hygiene Areas. There should be hygiene control measures for entry of
personnel, equipment, materials and ingredients. Access by personnel to Critical
Hygiene Areas should only be via a personnel changing facility. Routine access by
plant, equipment, ingredients, chemicals, etc., to Critical Hygiene Areas should be via
an airlock. Alternatives to maintain isolation may be approved on a case by case basis
where satisfactory control is demonstrated.
4.3.2
The boundary limits of Critical Hygiene Areas and Standard Hygiene Areas Signs
should be clearly identified for staff and visitors, by signage or other means.
4.3.3
Access into, and within Standard Hygiene Areas should be controlled in the following
areas to prevent contamination:
•
•
•
•
the area outside (including roofs, roof spaces, service rooms, basements, and
the external environment),
amenities
product and consumable goods stores,
areas of potential contamination from odours (e.g. ammonia compressors),
foreign matter, or micro-organisms.
Doors in high risk areas should be the “the kick open” type –i.e. no handles where
possible.
Locker areas, toilets, showers and handbasins should only be on the non-critical
hygiene side of the personnel changing facility and additionally toilets should be in a
18
separate room from the personnel changing facilities. Such facilities should be located
within the same building.
Routine access by personnel, plant and equipment to Standard Hygiene Areas should
be via a self-closing door. Routine access/egress of bags, drums, cans, or cartons
should be via a doorway, airlock or hatchway.
4.3.4
Ventilation air in Critical Hygiene and Standard Hygiene Areas
Refer Section 6.4
4.3.5
There should not be movement of forklifts or pallets from the standard hygiene area to
the critical hygiene area unless there are approved documented hygiene control
procedures in place.
4.3.6
Critical Hygiene Areas and Standard Hygiene Areas should operate under positive air
pressure relative to the outside, and Critical Hygiene Areas should operate at higher air
pressure than adjoining Standard Hygiene Areas, so that air movement is from the most
sensitive product areas outwards.
4.3.7
Doors designated as removable wall panels or emergency exit doors need not be air
locked or self-closing but should be managed to ensure they are not used for routine
access, e.g. alarmed and/or monitored.
4.4
Personnel Changing Facilities
4.4.1
All personnel access to a Critical Hygiene Area should be via a personnel changing
facility or a suitable alternative
The personnel changing facility should have provision for:
4.4.2
•
•
•
•
exchanging or covering footwear,
exchanging or covering clothing,
covering hair,
handwashing and hand sanitising.
4.4.3
The personnel changing facility should be designed so that, when used correctly, it will
minimise the transfer of contamination into a Critical Hygiene Area.
4.4.4
Ventilation should be provided to prevent stale or offensive odours developing, and the
air should flow from that area to an area of lesser hygiene status.
4.5
Air Locks
4.5.1
Airlocks should be provided for routine access into and out of a Critical Hygiene Area for
all items of plant, equipment, ingredients, chemicals, etc. Some packaging materials
may also be transferred into a Critical Hygiene Area via an airlock. Airlocks should
have provision for cleaning and sanitising all items expected to pass through the airlock.
For entry and exit of large pieces of equipment, refer to Section 5.9.
For the entry of packaging material refer to Section 5.6.1
19
4.5.2
Airlocks should be designated as Standard Hygiene Areas.
4.5.3
The doors at each end of an airlock should be fitted with an interlocking device to
prevent both doors being open simultaneously. The interlocking device should be
capable of being over-ridden upon activation of the fire alarm.
4.5.4
Air locks that are only intended for equipment and materials transfer should not be used
for personnel for direct entry into Critical Hygiene Area.Airlocks may also be required
between internal processing areas to control air flow patterns.
4.5.5
All airlock doors should be well-fitted and self-closing to minimise the ingress of pests
and contamination.
4.6
Staff Amenities
Staff amenities include cafeterias, locker areas, showers and toilets.
4.6.1
Staff amenities should not be located in a Critical Hygiene Area. Access between staff
amenities and a Critical Hygiene Area should be via a personnel changing facility. A
café bar may be provided in a Critical Hygiene Area for the preparation and
consumption of refreshments. Raw food should not be taken into a Critical Hygiene
Area.
4.6.2
Lockers provided must ensure that protective clothing is adequately protected from dust
and other contaminants. (including boots/freezer jackets/aprons etc).There should be
adequate facility for workers boots/aprons etc
Staff amenities should be located so that staff required to work in the Critical Hygiene
Area are not required to cross contaminated areas, such as tanker access routes,
before entry to the personnel changing facility. Locker areas, toilets and showers
should be located outside both standard and critical hygiene areas. In addition toilets
should be in separate rooms from the personnel changing facility, accessed from the
non hygiene side of the changing facility, and where possible within the same building.
4.6.3
Handwashing facilities should be provided in each toilet complex. Taps should be
electronic eye-, knee- or foot-operated, to minimise the transfer of contamination.
Hand drying facilities should be provided within easy reach of each hand basin. Single
use paper towels or electronic eye-operated hot air driers should be used. Where
disposable paper towels are used, a suitable receptacle for used towels should be
provided.
4.7
Separate Room Requirements
Separate rooms should be provided for areas where processing difficulties or
contamination are possible.
20
Note that wet areas should be in separate rooms from dry areas.
Energy and services plant and workshops should be in separate rooms from, and
should not open directly into, Critical Hygiene Areas, Standard Hygiene Areas, or
storage areas involving dairy products or dairy product ingredients, except where these
areas have been designated Critical Hygiene Areas or Standard Hygiene Areas, and
are maintained and environmentally controlled to the level specified by that
classification.
4.8
Milk Reception and Treatment Areas
Milk reception and treatment areas should be situated so as not to be thoroughfares
between Critical Hygiene Areas and amenities.
Raw milk processing equipment should be designed to minimise contamination (e.g.
fully enclosed or covered at all times) of the controlled environment in which it is
located.
In milk reception and treatment areas, the pasteurised product should be fully enclosed,
so that contamination by aerosols, etc., is not possible.
4.9
Tanker Unloading, Loading and Washing Areas
4.9.1
Tanker area location
Areas used for washing the outside of tankers should be segregated from processing
areas, staff access ways and amenities (refer to Section 3.3) and / or controlled so as to
prevent contamination.
4.9.2
Tanker pad
Tanker loading, unloading and washing areas should be paved with an appropriate
material such as concrete. Bitumen should not normally be used.
4.9.3
Tanker area drainage
Tanker loading, unloading and washing areas should be designed to prevent ponding
and prevent back-up in the drainage system. Drainage from these areas should be
collected and disposed of through the factory's effluent disposal system.
4.9.4
Tanker area canopies
Tanker bay canopies are not obligatory, but where provided they should be made
birdproof to prevent roosting and nesting.
4.9.5
Tanker fittings
There should be adequate provision for storage of pipes and fittings used in the tanker
areas. Racks should be provided for all hoses so that these are not lying on the tanker
bay floor. Where possible all hoses/pipes to be capped off when not in use.
21
Hoses should be clearly identified (preferably colour coded) to distinguish product lines
from CIP lines.
22
5.0 Design and Construction of Buildings
5.1
Floors
Consideration should be given to ensure that the floor materials have appropriate properties for
the area (i.e. water, chemical, mechanical and chemical resistance properties)
5.1.1
Floors and floor jointing compounds should be installed in accordance with
manufacturers recommendations and in accordance with section 5.4.
Unprotected concrete finishes are generally unsatisfactory for floors in manufacturing
and processing areas, and their use should be restricted to areas where porosity and
low chemical resistance would not cause problems.
Floors should be designed and laid to minimise the possibility of cracking.
Metal floors should be constructed and installed so that they are impervious to water
and crevice-free.
The junction of floors with walls, nibs and plinths should be coved. Preformed coving
that has a hollow cavity behind it when installed should not be used in Critical Hygiene
Areas or Standard Hygiene Areas.
5.1.2
Floors in wet processing areas should be installed and maintained so that there are no
low or depressed areas that are undrained and so would allow pools of water to
accumulate. Floors in dry processing areas, including overhead decking and walkways,
should be adequately graded and should be provided with drainage that can be
mechanically sealed (refer Section 6.7).
Water from predominantly wet areas (e.g. casein make rooms) should not contaminate
dry areas. This can be prevented by, for example, having wet areas at a lower level
than adjoining dry areas or nib walls at doors.
5.2
Walls
5.2.1
Wall finishes in Critical Hygiene and Standard Hygiene Areas should comply with
Section 5.4 and installed so that walls are impervious to moisture and dust.
Unprotected concrete and plaster finishes are generally unsatisfactory for walls in
Critical Hygiene or Standard Hygiene Areas and should only be used where their
porosity and low chemical resistance would not cause problems.
Unprotected concrete blocks are not suitable as a surface finish in Critical Hygiene or
Standard Hygiene Areas. If concrete blocks are used, they should be finished to ensure
23
the elimination of small pits and pin-holes. Cement bagging, cement render or plastering
should be used where the applied surface finish is not capable of filling the pin holes.
Courses between concrete blocks should be finished flush or to a radius of not less than
12 mm. The back side of concrete block walls should be sealed to prevent moisture
migration causing damage to the applied inner surface.
5.2.2
All joints (including floor and ceiling junctions) should be sealed with a suitable
compound, or otherwise made impervious to moisture and dust. All interior walls should
be readily cleanable.
5.2.3
Because Expanded polystyrene (EPS walls), or similar, are susceptible to mechanical,
chemical and heat damage, special conditions apply when using this material:
•
In wet areas the bottom of panels should either be placed on a nib wall or
coated with a protective specialist finish. The nib wall or specialist coating
should be at least 400 mm high.
•
In wet processing areas panels should be finished with a coating resistant to
chemical attack.
•
Areas of panel subject to regular chemical, salt, whey, steam or hot-water
spillage should be protected from damage by a suitable inert buffer plate or
stainless outer skin in affected areas.
•
Where the ends or sides of panels are not fully covered by the skin of an
adjoining panel or by a structural member the exposed portion of the interior of
the panel should be capped and effectively sealed to make it insect, vermin,
water and dust proof.
•
All panel jointers, base channels, cornices and coves should be sealed with
suitable sealants to provide a crevice-free finish.
5.2.4
Walls should be designed to minimise condensation, e.g. with insulation or by
controlled environment.
5.2.5
Where rooms are built within manufacturing rooms in such a position that an
inaccessible cavity is formed (a) between the top of the room and the ceiling above, or
(b) between the walls of the room and the existing wall construction, such cavities shall
be made pest- and dust-proof.)
5.3
Ceilings
5.3.1
Ceilings in Critical Hygiene and Standard Hygiene Areas should comply with Section
5.4 and be installed so they are impervious to moisture and dust. Joints on both the
upper and lower surfaces of the ceiling lining material should be sealed with suitable
sealing compounds to provide a crevice-free finish.
Ceilings should be designed and constructed to minimise the growth of mould,
accumulation of dirt and condensation.
24
Appropriate methods of minimising mould growth and the accumulation of dirt and
condensation include proper movement of ventilation air and sloping ceilings with
ventilation at the highest points.
5.3.2
5.3.3
Special additional conditions apply when panel ceilings are used:
•
In wet processing areas and areas where panels are subject to regular
chemical, salt or steam exposure, they should be finished with a coating or
material that is resistant to chemical attack
•
Where the ends, sides or penetrations through panels are not fully covered by
the skin of an adjoining panel or by a structural member, the exposed portion of
the interior of the panel should be capped or flashed and effectively sealed to
make it insect, vermin, water and dust proof.
Where there is a space between the ceiling and roof, it should be accessible from
outside the hygiene areas so that the roof can be checked for leaks and properly
maintained.
Ceilings in wet processing areas should be designed to control condensation (e.g.
insulation, controlled environment).
5.3.4
Surfaces of ceilings and ceiling spaces should be able to be easily cleaned and in
such a way that food safety is not compromised.
5.4
Interior Finishes
5.4.1
Introduction
The use of appropriate interior finishes for the walls, floors, and ceilings in the Critical
Hygiene, Standard Hygiene and storage areas of dairy factories can help prevent
contamination of the product.
Design detail should minimise any potential hygiene hazards such as ledges or
interfaces between incompatible materials.
Interior finishes should be selected so as to be suitable for the area and duty to which
they apply and be applied/ installed in accordance with manufacturers instructions.
5.4.2
Cleanability
The material should be:
•
•
5.4.3
adequately cleaned by normal procedures for that area of the dairy factory
without damage to the surface
free from cracks and crevices.
Resistance to water and water vapour
Finishes materials are to resist water and water vapour.
25
5.4.4
Resistance to chemicals
The material and its finish should be resistant to chemicals used in the area concerned.
Where highly concentrated chemicals are used in normal production areas, it may be
necessary to provide drip trays under valves and flanges to prevent damage to normal
finish materials.
5.4.5
Toxicity
Materials should not release toxic substances in their completed or installed forms.
5.4.6
Durability
The material should be sufficiently durable for the area in which it is used, e.g.
•
•
•
•
5.4.7
resistant to chipping, flaking, delamination and shrinkage
able to withstand long periods of exposure to heat and water
resistant to abrasion
able to withstand machinery vibration.
Resistance to thermal shock and thermal fluctuations
Consideration should be given to the thermal properties of materials to ensure they are
suitable for the conditions in which they are to be used.
5.4.8
Recommended properties
Interior finish materials should also have the following properties:
Ease of repair
•
The material should be easily repaired, any damage should not be likely to
spread, and the damaged areas should be usable soon after repairs are
completed.
Staining and bleaching
•
Wall materials should not stain or bleach when splashed with milk or milk
products, acids or alkaline solutions, or the other chemicals normally found in
dairy factories.
Traction
•
5.4.9
Floors should be non-slip whether wet or dry.
Glass
26
Glass, where used as an interior surface finish in windows, doors and mirrors, should be
fit for purpose.
Glass should not be used where there is a risk of product contamination. Where there
is no practical alternative to the use of glass e.g. pH probes, there should be adequate
controls in place to ensure that contamination has not occurred.
The interior surface of glass should be flat and smooth, so that it can be easily cleaned.
5.5
Penetrations
5.5.1
Where product lines, service lines, ducting and trunking pass through walls, ceilings or
floors, they should be flashed and sealed (using appropriate materials) to eliminate
crevices on both the interior and exterior surfaces.
5.5.2
Where any pipe, wire or duct passes through any ceiling, floor or wall, the gap, whilst
allowing for possible pipe expansion, should be sealed to prevent water seepage,
harbourage of pests and the entry of insects and vermin from either side. Electrical
ducting should be sealed to prevent the access of insects and rodents.
5.5.3
Flashings and seals around penetrations should not compromise the fire rating of the
wall, ceiling or floor containing the penetration.
5.6
Wall openings
5.6.1
Openings from critical hygiene areas through which drums, cartons, cans, bags etc. are
handled in rapid succession, that make the use of an airlock impractical, should be
protected by properly constructed flaps, strips or air curtains. These openings should be
the minimum size necessary to allow passage of the containers, and should be sealed
when not in use to prevent building air pressure loss and the entry of vermin and
insects. This will normally require that conveyors have a removable section at the door.
5.7
Windows
5.7.1
Windows in Critical Hygiene and Standard Hygiene Areas should not be able to be
opened and easily cleanable.
5.7.2
Opening windows may be used in non-dairy material/product processing or storage
areas. Insect screens should be fitted to opening windows and should be fixed so that
insects cannot get past them and enter the factory.
Insect screens should be mounted either on the outside of the window or flush with the
window seating to prevent dead insects and other foreign matter collecting on the
window ledge.
5.7.3
Where double glazing is used, the cavity between the panels should be sealed to
27
prevent the entry of dust and insects and condensation forming.
5.7.4
In Critical Hygiene and Standard Hygiene Areas, windows should be as flush as
practicable to the inside wall. Window ledges should be minimised and should be able
to be inspected and cleaned.
Window frames should be sealed and there should be no crevices between them and
the adjoining wall structure.
Window framing joints and corners should be sealed and crevice-free.
5.8
Doors and Doorways
5.8.1
Doors, door jambs and frames in Critical Hygiene and Standard Hygiene Areas should
be made of suitable materials for the environment.
Doors, door jambs and frames should be sealed and there should be no crevices
between them and the adjoining wall and if, applicable, the floor. Doors in Critical
Hygiene and Standard Hygiene Areas should be self-closing and, except where there is
conflict with emergency exit requirements, should close with the internal pressure rather
than against that pressure.
5.8.2
Roller doors, sectional slide-over doors, concertina doors, folding doors and other
multi-section doors that are difficult to clean should be avoided if possible in Critical
Hygiene Areas and Standard Hygiene Areas.
5.8.3
Emergency exit doors which are kept closed except during an emergency need not be
airlocked. An emergency exit door should be able to be opened from the inside only. A
system to verify the integrity of exit points and identify unauthorised use, should be
incorporated into the design of the door unit, e.g. an alarm activated by the opening of
the door.
5.9
Removable Wall Panels
To allow for the entry and exit of large pieces of equipment from Critical Hygiene or
Standard Hygiene Areas, removable wall panels may be provided as part of the main
wall construction.
These panels should be a sealed unit and should be sealed tightly to the adjacent walls,
floor and, if applicable, to the ceiling. They should be fixed shut to prevent unauthorised
use.
The interior surface of removable wall panels should meet the requirements for interior
wall finishes (refer Section 5.2).
5.10
Stairs, Decks and Walkways
5.10.1
Stairs, decks and walkways should not be above open processing or packing
equipment.
28
All stairs, decks, walkways and associated handrails sited where they could cause a
hazard to product in Critical Hygiene or Standard Hygiene Areas should be constructed
of impervious material and have up-stands. Up-stands should be not less than 150 mm
high. All seams in metal stairs and walkways should be continuously welded (or stitch
welded with the application of sealant) and tubular handrails should have fully sealed
ends.
Where the process is fully enclosed and there is no danger of product being
contaminated, open grid type decks and walkways may be used.
5.10.2
All stairs, decks and walkways should be constructed to prevent the ponding of water
and should be sloped to drain points.
5.10.3
Stairs in Critical Hygiene and Standard Hygiene Areas should have closed
treads and risers, except that the bottom riser should be designed to allow for easy floor
cleaning.
5.11
Ledges and Other Protrusions
5.11.1
In Critical Hygiene and Standard Hygiene Areas, ledges should be avoided or if
required should be as narrow as possible as they may collect soil and become a source
of contamination.
5.11.2
Overhead trusses and beams should be fully enclosed and crevice-free. Footings and
ledges at the base of walls should be easily cleanable. Interfaces between exposed
decks and beams should be fully sealed to eliminate crevices, either by continuously
welding them or by using suitable flexible sealants.
5.11.3
Ventilation ducts in Critical Hygiene and Standard Hygiene Areas may be installed lower
than the ceiling. This ducting should either be faced continuously to the ceiling so that
there are no ledges or suspended at a height which allows ready access for regular
inspection and cleaning (see Section 6.2).
5.11.4
Electrical wiring and dry service piping may be routed through ceiling spaces or service
tunnels to keep it external to hygiene areas. Routing of product, steam, water, and
other liquid service piping though ceiling spaces and other cavities should be avoided to
minimise undetected leaks and related hygiene problems. Process piping and storm
water drains should not be placed in inaccessible wall or ceiling cavities. Where
electrical wiring enters Critical Hygiene or Standard Hygiene Areas, it should be sealed
at the hygiene interface.
5.11.5
Whichever system is utilised the outcome should be cleanable (e.g. cable tray or ladder
rack) or contained (e.g.conduit). Wiring in exposed ladder racks should be accessible
and readily cleanable. Where wiring, service piping or process piping has to be
mounted on internal walls or ceilings, it should be sufficiently clear of the wall or ceiling
to allow cleaning between the surfaces. All switch and pipeline mountings and fixings
should be positively sealed to the walls or ceilings and should be free of crevices.
5.11.6
Where ledges are unavoidable in Critical Hygiene and Standard Hygiene Areas, they
29
should, where practicable, be sloped to facilitate ease of cleaning.
5.11.7
Roofs of internal rooms, the tops of indoor silos and other large pieces of equipment
should be capable of being readily cleaned and inspected. Where possible the walls of
rooms should be extended to the ceiling of the main room so that there is no internal
roofing.
5.12
Roofs
5.12.1
Roofs should be designed and built to prevent the entry of liquid, dust, insects, rodents
and birds.
5.12.2
All drainage from roofs should be piped to a storm water system. Gutters and
downpipes should be designed and constructed so that rainwater cannot contaminate
the interior of the factory. Gutters should be easy to clean.
Where internal downpipes are unavoidable, they should be capable of overflowing
without leaking into the building. Internal gutters should have a suitable overflow
system discharging to the outside. Internal gutters and downpipes should have at least
twice the capacity of well-designed external gutters.
5.12.3
Access to roofs should be from outside the building.
5.12.4
Roof penetrations should be minimised wherever practical.
30
6.0
Building Services
6.1
Ventilation Systems
6.1.1
There should be a well designed ventilation or air conditioning system for each
processing area to minimise condensation on walls and the ceiling throughout the range
of operating conditions. The ventilation system should provide satisfactory working
conditions. Mould growth is inhibited by relative humidities below 80%; the ventilation
system should be designed to keep the relative humidity below this level during normal
processing conditions.
It is recommended that where there is a risk of mould growth that the ventilation system
continue to operate to during periods of plant shutdown.
6.1.2
Equipment which releases a large amount of heat or moisture may be isolated in a
dedicated room or the equipment may be covered and vented.
6.2
Design of Ventilation Systems
6.2.1
Filters should be serviced from the dirty side of the air filter bank to prevent
contamination.
Fans should sit in and draw air directly from a fan room, with the air supply to the room
being via filters.
6.2.2
Reference should be made to the following in the design of ventilation systems:
•
ASHRAE Handbook—HVAC Applications – 2003
•
AS 1668.2-2002 : The use of ventilation and airconditioning in buildings - Ventilation
design for indoor air contaminant control
•
AS 4254-2002 : Ductwork for air-handling systems in buildings
•
HVAC Duct Construction (SMACNA), Sheet Metal and Air Conditioning Contractors'
National Association (USA)
6.2.3
Ducts should be fabricated according to good manufacturing practice and the ventilation
system installed to meet AS 1668. In particular:
•
Air filters should be readily accessible.
•
Ducting should be waterproof, fitted with drains with valves at its low points and
be designed and installed to prevent pooling.
31
•
Ducting should be able to be readily cleaned and inspected on the inside.
Inspection points should be provided and diffuser grills should be removable for
cleaning.
•
Ducting should be sealed to prevent air leakage.
•
Where ducting is insulated, the insulation will be installed in such a way that it
cannot enter the air stream.
6.2.4
Where air conditioning units are used or air is otherwise heated or cooled, fins on
radiator and evaporator banks should be accessible for inspection, cleaning and
sanitising. Condensate collection trays should be accessible for inspection, cleaning
and sanitising. Fins and trays should be fabricated from materials that can be cleaned
and sanitised. Product contact air should be filtered after the radiators.
6.3
Air Inlets
6.3.1
Air inlets should be located in clean areas. Where an inlet draws air from outside, it
should be at least 1.5 m, and preferably 3.0 m or more, above the ground to minimise
fouling of the filters. Where air is drawn from inside the building, the intake should be at
least 1.0 m above the floor. Where air is drawn from above the roof, the air intakes
should be mounted 1.0 m above the roof surface. Air inlets should be located well clear
of exhaust outlets so that cross contamination is prevented.
6.3.2
All air inlets to the factory should be protected against the weather. All air filters and
roughing filters should be spaced sufficiently far back from the weather louvres to
prevent rain and drizzle reaching them; a minimum of 1.00 m is recommended.
6.3.3
Screens should be fitted to the outside of inlet louvres to stop birds nesting and insect
entry. Insect screens should be able to be easily cleaned and fitted to the inside of the
louvres. Where lighting is installed in the area of the louvres and filters it should be
designed to minimise night attraction of insects to the air inlet area.
6.3.4
The frames for holding filter panels should be designed so that no air by-passes the
filters. Access doors for filter maintenance should be on the upstream side of the final
filter and should not open into Critical Hygiene Areas. Where air supply fans are located
downstream from the final filters, filtered air should be ducted directly to the fans.
6.4
Air Filtration
6.4.1
Filters can be classified according to their efficiency as described in Table 7.4.1. This
classification is based on European Standard EN 779; which uses the G and F prefixes,
and European Standard EN 1822 which uses the H and U prefixes listed in Table 7.4.1.
This classification system is similar to the previously used DIN 24-185 standard which
used the EU 1 to EU 9, and EU10 to EU 17 equivalent classes.
32
Table 7.4.1: EN779 and EN 1822 Air Filter Classification System
EN 779
Filter Class
Average
arrestance of
synthetic test dust
(gravimetric
measurement) (A%)
ASHRAE 52.1 (or EN
779)
G1
G2
G3
G4
A ≤ 65
65 ≤ A < 80
80 ≤ A < 90
90 ≤ A
Filter Group
Primary filters
to collect
coarse dust.
Secondary
filters to
collect and
retain
atmospheric
dust particles
HEPA filters
(High
Efficiency
Particulate
Air), for
specific small
particulate
control
ULPA filters
(Ultra Low
Penetration
Air),
F5
F6
F7
F8
F9
Average dust spot
efficiency (opacity
measured) (E%),
atmospheric dust.
ASHRAE 52.1 (or EN
779)
40 ≤ E < 60
60 ≤ E < 80
80 ≤E < 90
90 ≤ E < 95
95 ≤ E
EN 1822
Filter Class
H10
H11
H12
H13
H14
EN 1822 MPPS %
efficiency
85.0%
95.0%
99.5%
99.95%
99.995%
U15
U16
U17
EN 1822 MPPS%
efficiency
99.9995%
99.99995%
99.999995%
Filters should be designed and installed following manufacturers specifications and be
capable of producing air for safe food production.
6.4.2
Where there is potential for air to present a food safety risk ventilation air to Critical
Hygiene Areas should be filtered through air filters of at least Class F5 Where food is
manufactured which is intended for consumption by sensitive populations (eg. infant
33
formula or pharmaceutical) consideration should be given to the adoption of an
appropriately higher standard.
All ventilation air to Standard Hygiene Areas should be filtered through air filters that
comply with Class G3.
Where filters of higher standard than G3 are used then filter banks should be fitted with
pre-filters to meet at least Class G3.
All stages of filtration should be fitted with a pressure differential measuring device.
The air velocity at the filter media face should not exceed the maximum value specified
by the manufacturer.
6.4.3
Final filter media designed to be disposable should not be washed.
Fibres in final filter media should be securely held in place (e.g. by binding agents or
backing material) to prevent fibres being shed.
6.4.4
Where washable filters are used, safe removal, transport and washing procedures
should be in place. In all cases the filter design and material must be fit for purpose.
6.5
Ventilation Air Distribution and Extraction
6.5.1
Ventilation air should be circulated in a way that there are no dead spots. Adjustable air
distributors are recommended.
6.5.2
Ventilation ducting should be fitted so that it does not form ledges.
6.5.3
Inlets and exhausts should not be placed in positions which would allow condensation
or debris to fall and contaminate product e.g., above open vats.
Exhaust outlets should be designed and built to prevent the entry of water, insects,
vermin and birds. They should be sealed and free from crevices on both the internal and
external surfaces.
Exhaust outlets should be installed along the apex of the ceiling to make the maximum
use of natural convection. It may be necessary for additional extraction units to be
placed above sources of heat or moisture in the room. The design should take into
account the prevailing wind conditions.
6.5.4
Critical Hygiene and Standard Hygiene Areas should always operate at a minimum
positive air pressure of 40 Pa (4 mm water gauge). A design pressure of 60 Pa (6 mm
water gauge) is generally considered adequate to achieve this. The Critical Hygiene
Areas should operate at a higher pressure than the adjacent areas of the factory so that
air flow is outward from the Critical Hygiene Area. The factory should be maintained
under positive pressure outside processing times. Ventilation systems should be
balanced and periodically checked to ensure that design pressures are achieved.
6.5.5
Precautions should be taken to eliminate excessive dust in any room where a dusty or
34
powdered product is handled. Well designed local extraction hoods should be used as
necessary.
6.6
Water
Dairy processing water meets the NZFSA requirements for dairy processing water –
Dairy Processing Specification and approved criteria.
Non dairy processing water is any water that does not meet the definition of dairy
processing water.
Dairy processing water shall be used for:
•
•
•
•
•
•
•
all water coming into contact with any food or product contact surface and all
water used as an ingredient
cleaning all rooms where food is processed or packed
all eating rooms and handwashing facilities
all hoses in processing and packing areas
defrosting refrigeration coils in air chillers
water seals in product pumps
all fire fighting sprinkler systems where there is a risk of the water contaminating
product during processing.
Non dairy processing water, of an adequate standard for the purpose, may be used for:
•
•
•
•
•
•
toilets and urinals (flushing only)
factory exterior washing
condensers
fire hydrants
washing down external sumps and drains.
fire fighting systems, including sprinklers, where the hygiene areas and product
contact surfaces are completely cleaned and sanitised after any system
activation and prior to any further processing.
Non dairy processing water shall not be used in such a way that it constitutes a food
safety risk to the product. Such uses are described in dairy processing approved
criteria.
6.6.2
Identification of water lines
Regulation 17 of the Water Supplies Protection Regulations 1961 requires that
companies colour-code, or otherwise suitably identify, their dairy processing and
non-dairy processing water lines. This colour coding is not required where the water
comes exclusively from a public water supply. The requirements of the Water Supplies
Protection Regulations 1961 shall be observed.
Lines should be identified at all junctions, valves, outlets, both sides of wall penetrations
35
and at any other place where identification is necessary.
The identifying code should meet NZS 5807: Industrial Identification by Colour, Wording
or Other Coding
6.6.3
Contamination of dairy processing water
Care should be taken to ensure that there incompatible fittings between the dairy
processing and non-dairy processing systems.
Dairy processing water could become contaminated within the distribution system, e.g.
by non-dairy processing water supplies, back siphoning, dead ends in the lines of the
distributing system and pollution in the storage tanks.
Cross-connections between dairy processing and non-dairy processing supplies shall
not be permitted, unless there are adequate controls to prevent any possible
contamination of dairy processing water. Unused or dead-ended lines in the reticulation
system shall be closed off to isolate them from the reticulation system. All dairy
processing water storage tanks shall be effectively covered and protected to exclude
light and prevent contamination. Backflow prevention should be provided where any
potential of siphoning or backflow exists.
6.6.4
“Re-use” Water
Care should be taken in the use of “re use” water (e.g. UF/ RO permeate, evaporator
condensate or cow water) to ensure that the food safety of the dairy product/ material is
not compromised.
6.6.5
Handwashing facilities in processing areas
Handwashing facilities, including detergent and sanitisers, should be provided as near
as practical to the entrances to Critical Hygiene Areas and Standard Hygiene Areas.
Signs should be posted next to each hand basin instructing staff to keep their hands
clean.
Hand basins should be made of suitable material e.g. stainless steel and of hygienic
design and have an adequate supply of warm dairy processing water. Taps should be
foot-, knee- or electronically-operated. Hand-operated taps are not suitable. Drainage
from hand basins should be piped to drain.
Hand-drying facilities should be provided within easy reach of each hand basin. Paper
towels, roller towels or hot air driers may be used. Hot air driers should not be located
close to powder handling, storage or packing areas as there is a danger of explosions
caused by high dust loadings in the air. Where disposable paper towels are used, a
suitable receptacle for used towels should be provided.
6.6.6
Reticulation of dairy processing water for cleaning
Dairy processing water should be reticulated throughout the plant in quantities sufficient
for all operating needs and under enough pressure for effective cleaning. A sufficient
36
number of hoses should be provided to facilitate effective cleaning. There should be no
dead legs in the reticulation piping system.
6.6.7
Fire fighting systems
Water distribution systems for automatic sprinklers are subject to condensation and
rust; therefore should be designed and constructed (e.g. stainless steel) to minimise
food safety impact in food processing areas.
6.6.8
Lagging
Cold water pipes shall be lagged wherever condensation from them could enter the
product.
All pipes operating below 10 °C should be insulated and covered with a suitable
material or designed to prevent dripping condensation and therefore potential product
contamination. Refer Section 7.2.
6.7
Drainage
Drainage channels and outlets should be directed or designed so as not to compromise
the integrity of the hygiene zones or product safety. eg. flow to be directed from critical
areas to less critical areas.
6.7.1
Drainage should be provided to remove liquid waste quickly from processing areas. It
should be sized to prevent wastes backing up into the building. All floors in wet
processing areas should have trapped drains. Point drains are preferred in Critical
Hygiene Areas rather than open channel drains, and they should be spaced appropriate
to the activity.
A floor slope of 1 in 60 is suitable on monolithic type floors, but a gradient of 1 in 50 is
preferred with tiles.
Liquid waste should be piped directly to underfloor drainage systems instead of spilling
on to the floor. Drainage from hand basins must not spill on to floors. Discharges from
self-desludging separators should be piped to a closed drain.
Open channel drains, where used in Critical Hygiene or Standard Hygiene Areas,
should have a fall of at least 1 in 60 and be coved to allow ready cleaning. These drains
should be deep enough along their length to prevent overflow and wide enough to allow
for cleaning.
6.7.2
All drains should be designed (by a water-filled gully trap or another effective means) to
prevent odours entering the processing areas. The drainage system should be designed
to ensure that water seals are not evacuated by downstream pressure differentials.
37
Water-filled traps used in normally dry areas should be sealed between periodic
cleaning. Threaded drain caps, or similar odour and pest preventers, should be used to
seal these outlets.
The drainage system should have rodding points outside the Critical Hygiene or
Standard Hygiene Areas so that blocked drains can be cleaned without contamination
occurring.
6.7.3
All drainage from roofs shall be piped to a storm water or process effluent system.
6.7.4
Drain inlets and open channel drain discharge points through factory walls should be
screened and water-sealed to prevent the entry of rodents and insects. Where water
traps can dry out, drain caps should be used.
Screens on drains should have apertures of not more than 12 mm across, to prevent
the entry of rodents.
6.8
Effluent and Liquid Waste Disposal
6.8.1
Factories should have an efficient effluent and liquid waste disposal system which
should always be maintained in good order and repair. All effluent lines (including sewer
systems) should be large enough to carry peak loads and should be constructed to
avoid contamination of dairy processing water supplies. Where drained by gravity,
effluent lines should not be less than 150 mm in diameter.
6.8.2
Effluent ponds shall be located at least 10 m away from any product factory and shall be
sited so that they do not create a nuisance or problem at the factory, e.g. from odours or
pests.
6.9
Sewerage
6.9.1
Toilet rooms should be ventilated and all opening windows or vents should be
adequately screened against insects. Toilet vents should be sited far enough away
from ventilation intakes that there is no possibility of cross-contamination.
Adequate handwashing facilities should be provided in each toilet complex, and should
comply with Section 6.6.5.
6.9.2
Toilets and urinals should either drain to an adequate septic tank system located at a
safe distance from any Critical Hygiene or Standard Hygiene Area, or be discharged
into the local sewerage system in a way that prevents any foul water entering the
building as a result of blockages. Toilet and urinal drain piping should not pass through
any Critical Hygiene Areas, nor should they be connected to any drainage system
passing under a Critical Hygiene Area. Drains should be of material and construction
that ensure no leakage of effluent.
6.10
Solid Wastes
38
Provision should be made for the transfer of waste from Critical Hygiene and Standard
Hygiene Areas to a waste holding facility (e.g. covered rubbish bin) before its removal
from site.
Waste containers should be designed to prevent access by pests and to avoid
contamination of product, dairy processing water, equipment, buildings and roadways.
Processing area operators should be able to dispose of waste without leaving the
processing environment.
Vehicles involved in waste removal should not cross pedestrian access ways leading
into process plants.
6.11
Signs
6.11.1
The dairy operator should display in the factory suitably large and prominent notices or
indicate by another means the need for good hygienic and housekeeping practices. The
signs should be erected in clearly visible and logically sited places throughout the
manufacturing premises.
6.11.2
These signs should generally have easily identifiable graphics included with the words,
so that a limited knowledge of the English language will not be a handicap to
interpreting them.
The notices should be made from a durable, impervious material. To aid visibility it is
recommended that the minimum size for the graphic signs is 250 × 300 mm.
6.11.3
These signs should specify:
•
•
•
the limits of the critical hygiene areas
that hands must be washed
that approved clothing must be worn
6.12
Lighting
6.12.1
Adequate lighting should be provided in all areas of the factory.
Recommended minimum light levels (during processing) at 900 mm above the floor, or
at the inspection plane, are:
•
•
•
•
•
•
external areas (e.g. silos and external valves) — 150 lux;
storage areas (e.g. ingredient stores) — 150 lux;
amenities (e.g. toilets, showers, locker areas and cafeterias) — 150 lux;
tanker areas (e.g. unloading bays and wash areas) — 300 lux;
milk treatment areas (e.g. raw milk reception, milk separation
pasteurisation) — 500 lux;
product manufacturing areas — 500 lux;
and
39
•
6.12.2
inspection areas (e.g. cheese trimming and wrapping rooms, powder bagging
areas and butter boxing areas) — 1000 lux with natural light colour correction.
All light bulbs and fluorescent tubes should be protected to prevent broken glass
causing a risk to food safety. Wherever possible plastic covers should be used.
Where protective fittings are made of glass it should be at least 5 mm thick. Similar
precautions should also be taken in product storage areas.
6.12.3
Light fittings should be sealed so that they cannot collect dust or moisture from the
processing area. Recessed light fittings should be flashed from within the ceiling space
so that dust, moisture, and insects cannot gain access to the light fitting or through the
crevice around it.
In Critical Hygiene and Standard Hygiene Areas, light fittings should be reasonably flush
with the ceiling panel and accessible from the ceiling space. Where this is not feasible,
they may be attached directly and parallel to the ceiling. Such installations should be
sealed to eliminate cracks and crevices between the light fitting and ceiling.
If neither of these methods is possible, light fittings may be hung from ceilings. When
suspended light fittings are used, the top of the fitting should be sloped to at least 45° so
that any debris will fall to the floor, or be obvious when the processing area is cleaned.
6.12.4
Lighting systems should be designed and constructed according to good light design
principles (see NZS 6703: Code of Practice for Interior Lighting Design). Good design
minimises shadowing and glare, reflections off finished surfaces and equipment, and
provides a light of suitable colour.
6.12.5
The maintenance of bulbs and tubes should be considered when siting lights.
40
7.0
General Requirements for Manufacturing
Equipment
7.1
Design of Equipment for Product Processing
7.1.1
Prevention of contamination
Equipment should be designed to protect its contents as much as practicable from
external contamination. Crevices and dead pockets should be minimised; if they are
present, they should be readily cleanable.
7.1.2
Inspection points
There should be a sufficient number of inspection points located so that the hygienic
status of the equipment can be readily monitored.
7.1.3
Internal radii
For internal angles of 135° or less, a radius of not less than 6 mm is recommended.
When the radius is less than 6 mm, the product contact surface of the internal angle
should be accessible for cleaning and inspection.
7.1.4
Springs
Springs should not be used as product contact surfaces.
7.1.5
Bolts, Nuts and Threads
Bolts, nuts and threads on product contact surfaces should be avoided. Where the use
of these is unavoidable, they should be secured and readily accessible for cleaning and
inspection. Nuts should be open-ended.
7.1.6
Seals, glands and bearings
Glands and bearings should not come into contact with product. Seals that come in
contact with product should be removable for inspection, maintenance and, where
appropriate, cleaning.
Mechanical rotary seals should be used rather than packed glands.
All lubricated bearings should be located outside the product zone. If adjacent to it, they
should be constructed with a seal at the entrance to the shaft into the product zone.
41
Equipment having seals and bearings should be so designed and fabricated that
lubricant cannot leak, drip, be forced into, or in any way contaminate the product zone.
All lubricants that may come into contact with product must be recognised as meeting
food grade criteria.
7.1.7
Openings
Openings on equipment, including those for hinged or removable covers, should have
raised edges of at least 10 mm or be fitted with a permanently attached sanitary fitting.
The purpose of the raised edge is to prevent extraneous material entering the product
zone.
7.1.8
Lids and doors
Lids and doors on equipment should be:
•
close-fitting, self-draining and sufficiently rigid to prevent buckling
•
designed so that any liquid or dry material on the exterior will not enter the
product or touch product contact surfaces.
Lids should have downward edges of at least 10 mm.
7.1.9
Corrosion
Equipment should be designed and manufactured to minimise conditions resulting in
stress corrosion, crevice corrosion or any other factors which could cause hygiene or
contamination problems.
7.1.10
Vibrating equipment
Where fans and other items of vibrating equipment are connected to stainless steel
ducting, a flexible coupling made of material with properties in accordance with Section
7.2 should be used.
7.1.11
Cleanability
All equipment and piping should be able to be cleaned either manually or in-place.
Equipment designed to be manually cleaned should be able to be readily disassembled
and reassembled.
7.1.12
Drainage
All equipment that can be wet cleaned should be self-draining and graded to drain
points, so that no pools of liquid are left after cleaning. A slope of 1:15 will generally
provide adequate drainage.
7.1.13
Glass
Glass should not be used in processing environments. Where its use is unavoidable
the glass should be suitable for its application and be installed and/or controlled so as to
42
prevent contamination of the product in the event of breakage (e.g. pH probes).
7.1.14
Screens, strainers and filters
All screening and straining devices should be readily accessible for cleaning and
inspection.
Suitable strainers should be installed on the suction side of the tanker discharge pumps.
Strainers should be installed in cleaning-in-place (CIP) circuits to prevent the blockage
of spray devices.
Duplex filters are recommended if the filter is expected to require regular cleaning.
7.1.15
Spray balls
Spray devices should be easily accessible, readily removable or easily dismantled for
periodic inspection and cleaning. They should be fitted so that they cannot fall into
product.
7.2
Materials
7.2.1
Product contact surfaces
Metals should be corrosion-resistant, non-toxic, non-contaminating and cleanable under
the conditions of intended use.
Non-metal materials should be non-toxic, non-contaminating, cleanable and durable
under the conditions of use and where relevant should be certified as food grade.
Where specific functional properties are necessary, e.g. bearing surfaces and seals,
carbon or ceramic type materials may be used. These materials should be inert,
non-porous, non-toxic, non-absorbent, non-tainting, insoluble, and resistant to
scratching and distortion by the environment of intended use.
Natural or synthetic fibres may be used for screening surfaces and flexible connectors.
These materials should be non-toxic, food grade where appropriate, easily cleanable
and manufactured to prevent loss of fibres.
7.2.2
Non-product conduct surfaces
All non-product contact surfaces should be made of corrosion-resistant material, or
material that is rendered corrosion-resistant.
Surface coatings in the vicinity of open product should be selected to prevent chipping
or flaking.
43
7.3
Fabrication
7.3.1
Surface finish
All product contact surfaces should be finished to an Ra value of no more than 1 µm. All
product contact surfaces should be free from imperfections such as pits, folds and
crevices.
7.3.2
Welds
The product contact surface of welded joints should be ground and polished to an Ra
value of no more than 1 µm, and be free from pits, cracks and slag and gas inclusions,
except that internal grinding and polishing is not required on product pipelines.
Take-offs from stainless steel pipes should be formed or pulled holes to obtain the
correct weld finish.
It is advised that welders employed for these activities should be qualified to NZ4703
standard.
7.3.3
Plating
The minimum thickness of chromium plating should be 0.005 mm for all product contact
surfaces when that plating is on to stainless steel. For other metals the minimum
thickness of plating should be 0.05 mm.
7.3.4
Rubber and plastic materials
Where rubber and rubber-like or plastic materials forming product contact surfaces are
bonded to base metal, the bond should remain continuous and mechanically sound
under the intended conditions of use.
7.3.5
Painted surfaces
Product contact surfaces should not be painted.
If non-product contact surfaces are painted, the finish should be resistant to cleaning
systems and products in their intended areas of use (also refer Section 7.2).
7.3.6
Gaskets
Gaskets should be made of materials specified in Section 8.2 and installed in a manner
resulting in a true fit, to prevent protrusion into the product zone or the creation of
recesses or ledges at the joint.
Gaskets should be removable or bonded to one surface so that the bond is continuous
and mechanically sound.
44
8.0
Layout of Manufacturing Equipment
8.1
Equipment Spacing
There should be an adequate gap (recommended minimum of 75mm) to allow access
for cleaning and inspection between the equipment and walls.
There should be an adequate spacing between pieces of processing equipment to allow
access for cleaning and inspection.
Equipment which releases a great deal of heat or moisture (e.g. vacreators) should be
spaced sufficiently from walls or ceilings to prevent damage to buildings.
An adequate gap should be provided between a wall and the equipment or piping
running parallel to it to allow easy cleaning and inspection.
8.2
Equipment Mounting
The point of attachment of equipment mounted on a wall should be sealed to the wall
with a suitable sealant.
Vibrating equipment should be vibration-isolated, especially on metal decks.
Where equipment is supported on legs, these should provide minimal risk for material
entrapment. This can be achieved by sealing the legs to the floor or where this is not
practical using leg ends with minimal floor contact.
8.3
Clearance for Cleaning
There should be sufficient clearance between the base of the equipment and the floor to
allow the floor beneath to be cleaned.
As a guide:
Width
Minimum clearance
Up to 0.5 m
150 mm
0.5 to 2.0 m
200 mm
Over 2.0 m
250 mm
45
8.4
Explosion Ducts
8.4.1
Where processing equipment is fitted with explosion ducts which connect to the outside
of the building, the explosion duct should conform to the following:
8.5
8.5.1
•
Ready access should be provided into the ducting to allow regular cleaning and
inspection of the explosion door seal. An inspection port and interior lighting are
recommended.
•
The access to the ducting should have a locking system to ensure close-out
during operation of the processing equipment.
•
The ducting should be designed for wet cleaning.
•
The floor of the ducting should be free draining, i.e. built to prevent deformation
and subsequent ponding, and sloped to a drainage point with effluent piped to
the effluent drainage system.
•
The duct should be weatherproof.
Access to Silos
Vents and overflow lines for silos holding pasteurised milk and its derivatives, and
sanitary pipelines associated with the silos, should open to Critical Hygiene Areas. If it is
not practical to vent to Critical Hygiene Area, filtered vents that are to an equivalent
standard should be used.
Where manholes are required to be opened for cleaning they should open into critical
hygiene areas.
8.5.2
Manholes, vents and overflow lines for silos holding raw milk and unpasteurised milk
derivatives should not terminate in a Critical Hygiene Area. Where vents end outside a
processing area they should be fitted with suitable insect mesh.
8.5.3
Where additional protection is required to guard against accidental creation of a vacuum
within a silo, vacuum release vents may be fitted which vent to an atmosphere of the
same air quality as the process. Pressure release vents should be self resealing.
Where the rupture type are used the membranes should have activation detection, and
should be replaced in the event of rupture. All pressure/vacuum vents should form a
fully sealed, cleanable-in-place surface on the inside of the silo. Vents and membranes
should be designed and located to allow ready inspection and servicing.
46
9.0
Process engineering
9.1
Product Contact Steam
9.1.1
General
An adequate supply of steam, or another heating medium, should be provided to ensure
satisfactory processing and cleaning.
Product contact steam is steam intended to come in direct contact with product or
steam used to directly heat water which will come in contact with product. This steam
should be free from harmful or odorous substances and extraneous material.
Steam used in direct contact with food or food contact surfaces should not constitute a
threat to the safety and suitability of food.
9.1.2
Steam piping system
Product contact steam should be filtered to remove particles larger than 5 microns in
diameter. The filter and the steam line downstream from the filter should, as far as
practicable, be made of stainless steel to avoid recontamination with extraneous
material.
A means of sampling the product contact steam or condensate downstream from the
filter should be provided.
A check valve or other device should be fitted in the steam line to prevent product and
cleaning chemicals gaining access to all parts of the steam piping and fittings.
9.1.3
Boiler water
•
•
Only Approved Food Grade, non-toxic and non-tainting boiler water additives
should be used in product contact steam.
Boiler water treatment feed systems shall be to food grade standards.
9.2
Product Contact Air
9.2.1
Product contact air includes cooling air, drying air, conveying air, mixing and stirring air,
conditioning air and compressed air that may come in contact with product or product
contact surfaces. This air should be free from harmful or odorous substances and
extraneous material.
9.2.2
Product contact air should be filtered. The location of filters and design of ducts should
comply with Section 6.2 except that air to be compressed should be filtered upstream
from the compressing equipment.
47
Filters should be located and installed so as to be easily accessible for examination and
replacement. The filters should be protected from weather, water, product spillage and
physical damage.
All filters should be sealed in their holders and installed according to the manufacturer’s
requirements to prevent access of unfiltered air.
The minimum filter efficiencies should comply with Section 6.4, except that compressed
air filters may be alternatively specified as removing a minimum of 99.9% of particles 10
µm in size. Compressed air should be further filtered to comply with Table 9.2.1.
9.2.3
Air intakes for product contact air should be sited to comply with Section 6.3.
9.2.4
Compressed air lines should have oil and water removal devices to remove entrained oil
and water.
The compressed air should meet the requirements of 3A Accepted Practices for
Supplying Air under Pressure in Contact with Milk, Milk Products and Product Contact
Surfaces, No. 604-03 and the following standards:
Table 9.2.1: Compressed air quality
Solid
contaminants
Maximum particle
size (µm)
Maximum
concentration
(mg/m3)
1.0
9.3
1.0
Water
Oil (hydrocarbons)
Dewpoint of
compressed air
(°C maximum)
Maximum content
(mg/m3)
+2
0.01
Dairy processing Water
Refer to Section 6.6.
9.4
Refrigeration
9.4.1
General
Sufficient refrigeration capacity should be available to chill raw and microbiocidally
treated (e.g. heat treated) materials/product and maintain them at a temperature low
enough to ensure that there is no adverse effect on the hygienic quality of the product.
9.4.2
Refrigeration equipment
48
Equipment for re-cooling and compressing refrigerants should be located outside
processing or packing areas. The cooling air from the refrigeration plant, that might
contain ammonia, should not discharge into processing or packing rooms.
Only non-toxic freezing point depressants shall be used in systems where the chilling
liquid is immediately adjacent to milk or product. Food grade Monopropylene glycol and
glycerol are accepted non-toxic freezing point depressants.
Condensate from refrigeration units should be piped to the drainage system.
9.5
Product and CIP Piping
9.5.1
General Requirements
The construction materials, fabrication and installation of all product and CIP piping
should comply with this code.
9.5.2
Design
Cleaning solution velocity
The average velocity of the cleaning solution flow should be adequate for good cleaning
e.g. no less than 1.5 m/s or a Reynolds number of greater than 200 000 should be
generated during CIP.
Where pipes with diameters greater than 100 mm are used, special care should be
taken to ensure that stabilised air pockets cannot occur during cleaning.
CIP systems should be designed so that the suction intake of the primary circulation
pump is flooded at all times during the cleaning cycle, or an appropriate alternative type
of pump should be used(e.g. liquid ring).
CIP systems should be designed so that ponding of CIP fluid in tanks and vessels is
avoided.
Cleaning solution strength
Provision should be made so solution strength can easily be monitored.
Cleaning solution temperature
An indicating thermometer or a temperature recorder should be used to monitor the CIP
solution temperature.
Where CIP sets are used, the sensing element of the thermometer should be located in
the return solution line after the end of the circuit being cleaned.
49
The solution temperature should be automatically controlled by the use of a temperature
controller.
Inspection points
There should be an adequate number of inspection points on all milk and product
pipelines.
Inspection points in piping systems should be couplings in the product piping that can
be easily undone for inspection of the adjacent pipe. As a minimum, they should be
located at:
•
•
•
the outlet of each cleaning circuit;
where cleaning problems might be expected, e.g. where the pipe increases
in diameter;
at each high and at each low point of a piping network.
CIP-product segregation
The processing system and CIP system should be constructed and controlled to
positively prevent the intermixing of the product and the CIP solution, e.g. by venting the
gap between the CIP solution and the product with swing-bends, key pieces or valves.
Strainers
Strainers should be fitted into cleaning circuits The mesh size of the strainer should be
smaller than the hole size in the spray device. Strainers should be installed to enable
easy inspection.
9.5.3
Fabrication
Welding
Welds in product and CIP pipelines should be smooth and free from pits, craters, ridges
and embedded material. Welders should be qualified according to NZS 4703: 1985 or
an equivalent standard. Any unsatisfactory welds should be removed and the joints
properly rewelded.
Coverings for outside openings
Openings of sanitary pipelines to the exterior environment should be covered when not
in use. A stainless steel cap or a swing bend which closes the pipe when not in use is
satisfactory.
Self-draining requirement
All product and cleaning system pipelines should be sloped to drain points. The
recommended slope is 1 in 100 and it should not be less than 1 in 200.
Pipe supports
50
Pipe supports should be designed to provide adequate support without pipe sagging or
liquid retention in product and CIP pipework. Allowance for expansion and contraction
should be made.
9.6
Fittings
9.6.1
Materials
Plug-type or butterfly valves may have plugs or butterflies covered with rubber,
rubber-like or plastic materials which comply with Section 8.2. The material used should
have a composition which retains its surface and conformation characteristics when
exposed to the conditions of intended use, including cleaning and sanitising.
9.6.2
Fabrication
Where equipment or pipelines are to be cleaned in place, removable fittings may be
used with or without gaskets and should be designed to form flush or nearly flush
interior joints. Wherever possible “dead ends” should be avoided. Wherever not
possible to avoid “dead ends” pipework should be designed so that any “dead end”
distance is not greater than 1.5 times the pipe diameter.
9.7
Instruments
9.7.1
Pasteuriser temperature control systems
All pasteuriser temperature control systems shall comply with heat treatment
requirements of NZFSA Dairy specifications and criteria.
9.7.2
CIP temperature controllers
If they are used, temperature controllers located on CIP sets should control to an
accuracy of ± 2 °C, and be protected against damage at 100 °C.
9.7.3
CIP temperature recorders
If they are used, temperature recorders located on CIP sets should comply with the
following:
9.7.4
•
The scale range should be 20-85 °C.
•
The accuracy should be better than ± 1 °C in the range 60-80 °C.
•
They should be protected against damage at 100 °C.
Glass thermometers
51
Glass thermometers must not be placed into dairy material streams or installed so that
they come into contact with product or cleaning solutions.
9.7.5
Temperature sensors
Temperature sensors, including their protective pockets, should be able to be removed
from the equipment or pipeline they are installed on in order to test their accuracy.
9.7.6
Pressure measurement
Recording or indicating gauges should be of the sanitary diaphragm or pressure bulb
type.
52
10.0 Requirements for Specific Types of Equipment
The construction materials, fabrication and installation of all equipment should comply
with this code.
10.1
Storage Vessels and Vats
10.1.1
Fabrication
The base of the vent of a raw product storage vessel should be able to be fitted with a
filter suitable to prevent the escape of aerosols.
A means should be provided to prevent siphonage in the vent line.
A temperature sensor should be provided on all milk and liquid milk product vessels to
allow recording of temperatures during product storage and cleaning.
All silos and other liquid storage vessels should be able to be cleaned by mechanical
recirculation of the cleaning fluid (A strainer should be fitted in the CIP lines to assist in
the prevention of spray ball blockage.
All product contact surfaces should be self-draining.
The bottom pitch of tanks designed to be cleaned by recirculation of the cleaning fluid
should be at least:
•
•
1:15 for vertical tanks
1:50 for horizontal tanks.
The number of inlet and outlet ports in silos should be reduced to a minimum. They
should be placed near the bottom of the tank for ease of CIP. Where large diameter
pipes are required at the outlet, special care should be taken to ensure the outlet pipe is
properly designed and fabricated to ensure cleanability.
Vessels for the storage of skim or whole milk should be provided with sufficient agitation
to prevent thermal layering. The difference in temperature between the coolest and
hottest sectors of the contents within the vessel should not exceed 1 °C.
Hinged manhole doors should have the hinge attached to the outside of the silo. The
edge of the opening around the manhole should not protrude into the silo so that it
shields an area of the inside surface of the silo from CIP solutions.
10.1.2
Installation
Silos CIP systems should be installed such that the silo cannot be cleaned whilst
containing product. Ways of achieving this include:
53
•
•
key pieces in the CIP line which cannot be fitted unless the manhole is open
sensing devices which detect silo level and are interlocked with the CIP system.
Silo plinths should be raised so that the silo gullet is sufficiently above floor level so as
to achieve the self draining requirement.
10.2
Heat Exchangers and Pasteurisation Equipment
10.2.1
General requirements
Only non-toxic freezing point depressants should be used in systems where the chilling
liquid is used adjacent to milk or milk products. Mono-propylene glycol and glycerol are
acceptable non-toxic freezing point depressants.
In chilling systems where the chilling liquid temperature is lower than the freezing
temperature of the product, means should be provided to automatically control the
temperature and/or flow of the cooling medium to prevent the product freezing.
10.2.2
Fabrication of plate heat exchangers
Plate heat exchangers should comply with the requirements of the relevant sections of
this guideline.
Preferably a leak escape groove, open to the atmosphere at both ends, should be
provided to allow leakage past the gaskets to free drain, or differential pressure in
favour of the product.
10.2.3
Tubular heat exchangers
In tubular heat exchangers, all permanent joints in metallic contact surfaces should be
welded, except that tubes may be expanded and rolled into tube sheets or return
fittings. The resulting joint should be completely rigid and without pockets or crevices.
In tubular heat exchangers, the tubes should be supported in a manner to prevent
sagging. In designs involving two or more concentric tubes, where the exchanger will be
cleaned in place, a means should be provided of keeping the tubes equally spaced, as
long as this does not interfere with cleaning. All product contact surfaces should be
accessible for manual cleaning, unless it has been demonstrated that this is not
necessary.
10.2.4
Heat Treatment Equipment
All validated heat treatment equipment must comply with NZFSA Dairy requirements
relating to heat treatment.
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10.3
Milk and Milk Product Tankers
10.3.1
Fabrication
10.3.2
Baffles
Any baffles should be designed to allow access to all areas within the tank for
inspection. Compartments may be provided within the tanks.
10.3.3
Manholes
Manholes should be provided to allow easy access to each compartment. The upper
edge of the manhole surround should not be less than 10 mm higher than the
surrounding area. Manhole cover gaskets should be easily removable. The hinge for the
manhole cover should be on the outside of the tank.
10.3.4
Vents
A sanitary vent of sufficient free opening to prevent excess vacuum or internal pressure
should be installed. The air vent should be designed so that its parts are readily
accessible, easily removable and readily cleanable. The vent should be able to be fitted
with a filter suitable to prevent the escape of aerosols for the control of exotic animal
diseases.
10.3.5
Hoses
When not in use, the hose should be able to be secured to the tank in such a way that
prevents the entry of foreign matter and prevents the hose from falling off the tanker.
The hose should be fitted with a strainer with holes of a maximum of 10mm diameter
or equivalent free area.
10.3.6
Cabinets
A cabinet should be provided for the storage of milk samples and for the protection of
the milk sampling devices. It should be lined with a suitable material and should be
readily cleanable. The cabinet should be large enough and located so that there is
easy access to the sampling devices and the milk samples, and to assemble and
disassemble removable parts. Facilities should be provided to hold the supplier
records in good condition.
10.3.7
Sample containers
A container should be provided to hold supplier samples and should be insulated,
made of approved materials and dust-proof. The container should provide cooling
facilities to maintain the required sample temperatures.
10.3.8
Meters
If a milk volume measuring device is fitted it should be designed and installed in such a
manner, so as to not compromise food safety
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10.3.9
Thermometers
A temperature sensing device should be fitted to the inlet of the tank. When fitted it
should comply with the requirements of Section 9.7.5.
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